The latest instalment of ourweekly series, in which we use the Centre for Cities’ data tools to crunch some of the numbers on Britain's cities.

David Davis, our Brexiteering overlord extraordinaire, is in the business of negotiating our departure from the European Union.

Despite the fact that negotiations – led by David and his counterpart Michel Barnier – started only last week, they seem to have rather slipped down the agenda.

Admittedly, other things have happened, and we can’t expect the negotiations to ride top of the news agenda throughout the next 21 months or so until we actually get booted out of the EU in March 2019, but still: you’d hope we’d be able to sustain interest from at least the first week to the second.

In the long term, the key item on the negotiation agenda will be economics. Trade – and more specifically, exports – matter a great deal to us, and to our cities in particular.

If you were wondering about the subheading, here's the explanation. Image: Getty.

The Centre for Cities has some useful data here that gives a brief summative snapshot of the UK’s exports that we’ll have to try to protect – and expand on – in our deals with the EU and the rest of the world.

The key metric is exports per job: the value of the things we ship out – whether in terms of goods (stuff) or services (er, services) – relative to the number of people working to make those exports happen. In a very perfunctory way, the higher the number per job for a city, the better it’s doing in the exports market.

Without further ado, here’s a snapshot of the country.

There is no data for Belfast, so I can’t make any shady backhanded comments about the DUP, which is a shame.

To break it down further, the average value of exports per job across the country in 2014 was £15,690. Here are the cities around the national average:

Click to expand. Image: Centre for Cities.

Cities as diverse as Hull, Edinburgh, Oxford and Southampton all cluster around that average figure, accruing around £15,000 in exports per job.

But, as ever, it’s the extremes that are most interesting.

The least successful cities in terms of exports are, largely speaking, in the North. The value of exports per job in York is just £3,710; in Doncaster it’s £5,410, £6,680 in Wakefield, £7,420 in Barnsley, and £8,160 in Preston – to choose a selection of the bottom ten.

That being said, there are outliers here, too. Nottingham – hardly a northern city – exported just £5,770 in goods and services per job in 2014. For Exeter, which is about as southern as you can get, that figure was £5,940.

Exports in these cities are clearly struggling. Such low numbers suggest fragile trading ecosystems, that may be highly susceptible to stormy economic conditions as we struggle to whittle through the umpteen minute details necessary to survive Brexit..

At the other end of the scale, some cities are exporting like there’s no tomorrow.

London’s exports per job come out at £23,470, while commuter-belt hotspots like Aldershot and Slough accrue £24,660 and £27,560, respectively.

Given that the average salary in the UK hovers idly around the £27,000 mark, this is starting to look like very good news. If the value of exports per job can be roughly equal to the average salary for one job, something’s probably going well.

The top ten cities by exports per job. Click to expand. Image: Centre for Cities.

But those aren’t even the highest figures.

Worthing, of all places, clearly shows its worth (sorry) with exports per job of £29,640. Out on top, and ahead by quite a way, is Sunderland: its exports were worth almost £5b in 2014, which breaks down to £40,650 per job.

That moment when Theresa May rushed to comfort Nissan, in the first months of her premiership after the UK voted to leave the EU, suddenly starts to make sense. The firm’s plant in Sunderland is the UK’s biggest car-producing plant, and exports at least 80 per cent of all the vehicles it produces.

Who's steering us through this Brexit, anyway? Image: Mario von Berg.

Paul Swinney of the Centre for Cities – and a Sunderland native – puts it in stark terms. “If you didn’t have Nissan and the supply chain, Sunderland would be the 12th lowest exporter, rather than the highest.”

And we’d be missing out on £5bn in exports.

More importantly, of course, if Nissan can't export the cars from the UK easily, they'll just go somewhere else to produce them.

Most importantly of all, that will mean thousands and thousands of people losing their jobs. Which means thousands of devastated lives, hungry children, distraught families, and so on and forth.

Sunderland’s car factory, of course, is a world away from the vast pharmaceutical centre run by GlaxoSmithkline in Worthing, Britain’s second city for exports per job. What these figures show us is that the challenge faced by those making trade deals on our behalf is to secure trading systems that work as well for the cars of Sunderland as for the drugs of Worthing and the services of London.

And as much as anything else, these figures show what is increasingly clear about the UK – its divided nature. While some cities rake in billions from exports, others are barely breaking out beyond their own confines.

The deals we make as we go ‘out and into the world’ in the coming years face a formidable task: protecting the strong exports we already have pouring out of some of our cities, while trying to create the conditions for trade to flourish in the cities that have been left behind thus far.

It is impossible to overstate how high the stakes are throughout this process.

A prototype Skybus on display near Pittsburgh. Image: BongWarrior/Wikimedia Commons.

The late director George A Romero’s films are mainly known for their zombies, an association stretching from his first film, 1968’s Night of the Living Dead, to his last as director, 2009’s Survival of the Dead.

But many of them are also a record of Pittsburgh, the city he lived and worked in, and other locations in the state of Pennsylvania in the late 20th century. Martin (1978), for example, isn’t just a movie about a kid who thinks he’s a vampire: it’s a moving portrayal of the post-industrial decay of the Pittsburgh borough of Braddock.

Though born in New York, Romero studied in Pittsburgh and stayed in the city after graduation, shooting commercials as part of the successful Latent Image agency. It was in collaboration with advertising colleagues that he shot his debut Night of the Living Dead. On both that movie and subsequent films, Romero and his colleagues used their experience and connections from the agency to secure cheap and striking locations around the city and state.

It’s in Romero’s little-seen second film, 1971’s romantic drama There’s Always Vanilla, that a crucial scene touches on a dead end in the history of urban transport in Steel City.

In the scene Vietnam vet Chris, only recently returned to town after a failed music career, sees his father off on a train platform, after an evening where Chris got his dad stoned and set him up with a stripper. (It was the early 1970s, remember.) An odd little two-carriage metro train pulls up on an elevated concrete platform, Chris’ father rides away on it, and then Chris literally bumps into Lynn, whom he then both gaslights and negs. (It was the ‘70s.) You can see the scene here.

A screenshot from There's Always Vanilla, showing the Skybus through a chain link fence.

If you don’t live in Pittsburgh, you might assume that funny little train, still futuristic forty years on, is just an everyday way of getting around in the exciting New World. Who knows what amazing technology they have over there, right?

In fact, the Transit Expressway Revenue Line, more snappily referred to as the Skybus, not only doesn’t exist today: it hardly existed at all, beyond what we see in that short scene. In the 1960s there were plans to replace Pittsburgh’s street car system with a more up to date urban transit system. The Skybus – driverless, running on rubber tires on an elevated concrete track with power provided with an under rail system – drew enough support from the Port Authority and Federal Government for them to fund a short demonstration track at the Allegheny County Fair, at that point a local institution.

It’s this demonstration track and train that appears in There’s Always Vanilla. Film makers love isolated systems like this, or the UK’s many heritage railways, because they allow for multiple takes and a controlled environment. So it made sense for Romero to use this local curio rather than seek access to an in-use station.

The sequence in Vanilla shows that the Skybus system worked, and as a potential metro system it looks quite striking to this day with its curved windows and distinctive logo. But the proposed system wasn’t popular with everyone, and cost concerns and political wrangling stalled the project – until it was finally rejected in favour of a more conventional steel wheel on steel rail transit system.

The demonstration track was pulled up in 1980, although the small station and platform seen in the movie remains: Romero expert Lawrence Devincentz narrates a photo tour of the building on the blu ray of There’s Always Vanilla.

Vanilla was renamed and barely seen on release, but is now available as part of a boxset of Romero’s early works from Arrow Video, in ridiculously pristine 2K digital transfer. The Skybus is there too, a curio of Pittsburgh history caught on a few short minutes of film. Neglected back then, both seem considerably more interesting now.

‘There’s Always Vanilla’ is available on blu ray as part of Arrow’s ‘George A. Romero: Between Night and Dawn’ box set, and will receive a standalone release later this year.

Mark Clapham used to work in rail regulation, but now writes things like this. He tweets as @markclapham.

We notice that you're using ad blocker. If we can't support the site on advertising revenue, CityMetric will go the way of, I dunno, the Aldwych branch of the Piccadilly line. Which, let's be honest, would suck.

That's the bad news. The good news is that, if you contribute now, you can support CityMetric's quality, independent journalism another way - and this message will disappear for the next 30 days.